Math & Everyday
Coin Flip Simulator
Flip one coin or simulate thousands at once, with a running heads/tails tally.
🔒 Runs entirely in your browser — nothing here is ever uploaded
CalcoTools · Coin Flip Simulator · generated 9/5/2026, 4:03:35 PM
About the Coin Flip Simulator
Flips a virtual coin — one at a time or thousands at once — with a running heads/tails count and percentage split.
100% Free Runs in Your Browser No Sign-Up Required
How to use it
- Set Flips per click to 1 for a single flip, or a larger number to simulate many at once.
- Click Flip.
- Watch the cumulative Heads/Tails count and percentage update, or Reset to start over.
Formula
Each flip is an independent draw: Math.random() < 0.5 gives Heads, otherwise Tails — a true unweighted 50/50 event.
Worked example
Flipping 1,000 times typically lands close to 500/500, though any individual small batch (say, 10 flips) can easily land 7-3 or further off 50/50 purely by chance.
Recommendations
- • A run of several heads or tails in a row in a small batch is normal, not a sign of a 'streak' or bias.
- • The heads/tails split only reliably approaches 50/50 as the flip count grows into the hundreds or thousands.
Frequently asked questions
It uses the browser's Math.random() — statistically unbiased for a coin flip, though not cryptographically secure randomness. That distinction doesn't matter for this use case.